Good "Always on Top" utility?

Sunday, I tried several AOT utilities and never got one that really was “always.” I started with Firefox, but when I would open up a new window to do some work, the new window popped in to the AOT window. So I thought that if I had an AOT window in Chrome I could watch in that window and it would have no knowledge of what I might be doing with Excel, Firefox, etc. But whatever I opened up would get in front of the SOT (Sometimes on top…) window. Still had sound, but no picture. The ideal specs would be, in order:

  1. Actually always on top, regardless of whatever is being done with the PC.
  2. Resizeable.
  3. Movable.
  4. Keyboard hot key to toggle full screen and the AOT smaller window.

I am using Windows 10, but doubt that makes a difference.